1. Field of Invention
The field of this invention relates to hoses for carrying fluid materials (i.e. gas, liquid, solid particle mixes) and more specifically to hoses having a retractable and extendable means built into the hose itself.
2. Prior Art
The linearly retractable and extendible pressure hose was developed by Gary Ragner in 2001 and formally applied for in Utility application Ser. No. 10/303,941 filed Nov. 25, 2002, and Divisional application Ser. No. 11/234,944 filed Sep. 26, 2005. This prior art by the Applicant shows a linearly retractable and extendible hose structure that extends longitudinally along its length to provide approximately a five-to-one expanded-to-retracted ratio of both its length and its interior volume. This prior art designs by Ragner uses a hose body (see layers 32 and 34 in FIGS. 1A and 1B) that bulged outward between the coils of a biasing spring 36 in both its extended and retracted positions (see FIGS. 1A and 1B, respectfully). The disclosed improvements of the “linearly retractable and extendible pressure hose” comprise eliminating the bulging surface portion 37, and instead indenting that surface portion of the hose between the coils of spring 36. This places hose body (comprising layers 32 and 34), substantially within the biasing spring's volume (see FIGS. 4A-B, 5A-C, 6A-C and 7A-C). While the bulging outward of the hose body (layers 32 and 34), intuitively seems to be the best way to transfer interior hose pressure to the biasing spring, this arrangement causes three main problems that the new designs solve. The first problem is that the bulging hose body (convex between spring coils) is susceptible to wear and abrasion, and because of the very flexible nature of the hose, the hose body must be very thin and flexible. Thus, only a small amount of wear can cause such a hose to fail. The herein disclosed linearly retractable hose design indents the hose body substantially within the biasing spring's coils. This indenting of the hose body can help protect the hose body from abrasive surfaces because the biasing spring can make contact with these abrasive surfaces before the softer and more easily damaged hose body. With this type of hose design in its retracted position, the hose body is substantially protected form abrasive surfaces by the biasing spring (see FIGS. 4A through 7D). The exterior edge of the spring coils can make contact first with a flat abrasive surface to provide the very good wear protection. The spring's coils can be made of spring steel or other resilient material, which can be extremely abrasion resistant. Second, the strength needed for the hose body material under pressure is mathematically proportional to the diameter (and radius) of the hose material. Thus, the bulges require a proportionally stronger hose material than one that does not bulge out between the coils (note that this is somewhat offset by the support provided by the spring coils). By indenting the hose body intermediate between the coils, the effective radius at the center of the indentation can be significantly reduced (see FIGS. 4B, 5A, 6B-C and 7A-B), so that the physical strength of the hose body can be less than for the prior art design seen in FIG. 1A (for the same diameter cross-section biasing spring). Third, by indenting the hose body between the spring's coils, and having the hose body fold inside the spring when retracted, the overall volume of the linearly retractable pressure hose is significantly reduced in its retracted position compared to prior art linearly retractable pressure hose designs which fold the hose body outside the spring's coils.
The disclosed linearly retractable hose designs solves these problems as a direct result of having the hose body material indented between the spring's coils (see FIGS. 3A through 10C) or entirely within a tension wave-spring (see FIGS. 11A through 16C). For indented hose body designs, the flexible hose body is indented between the spring coils, and generally stay inside the outside diameter of the helical spring, both when extended and when retracted. However, as the hose ages it may bow outward under full pressure, but should still be designed to retract radially back inside the outside diameter (diameter defined by a specific radius from the central longitudinal axis of the hose) of the biasing spring when internal pressure is reduced. This way the hose body does not get in the way between the coils of the spring, is substantially protected from abrasion, and the overall size of the hose is substantially reduced compared to prior art designs. For hybrid tension wave-spring designs (see FIGS. 11A-12B, 15A-C, and 16C-D), the hose body is placed entirely within the tension wave-spring structure (also referred to as, hybrid tension wave-spring, hybrid wave-spring, and hybrid spring herein) with little or no bonding between the hose body 180 and tension biased wave-spring 154 along the length of hose 150 (see FIG. 11A). For hose 150, both hose body 180 and wave-spring 154 are only connected together at their ends where inlet connector 152 (faucet connector) and outlet connector 158 each connect to both the hose body and the wave-spring.
In the seventh presently disclosed “linearly retractable pressure hose” design, where the spring biasing is provided by a tension wave-spring (or hybrid wave-spring) the spring structure: 1) provides radial supports for the hose body and 2) completely surrounds the hose body providing physical protection. The interior hose body provides very little radial support and is contained radially by the biasing spring's circumferential strength. For wave-springs this strength comes from tension in the spring windings which are bonded together. Physical protection is provided by the wave-spring by providing only small openings between coil turns. This tight spacing protects the hose body from eternal damage, and allows the hose body to be made of very thin and flexible materials to provide very large extension ratios of 10-to-1 or more.
In FIG. 1A we see a prior art Linearly Extendable and Retractable Pressure Hose 30 shown in section view, cut longitudinally down its central longitudinal axis. Hose 30 is specifically designed to be a pressure hose. A biasing means (helical spring 36) is incorporated to bias the hose toward its retracted position. Biasing spring 36 can be a simple helical spring that extends along the full length of the hose. Spring 36 may be integrated with hose 30 in a number of different ways, such as, molded completely within hose 30 as shown in FIGS. 1A and 1B, or may be internal or external to hose 30. For designs with such internal or external biasing mean, the biasing means can be attached at the ends of hose 30. For the disclosed pressure hose, the hose body must be securely attached to the biasing means to provide the proper control over folding of the hose body within the biasing means (helical spring). In FIG. 1A, helix spring 36 is shown encapsulated between hose cover material 32 on the outside and hose cover material 34 on the inside, which provides a flexible elongated hose body for the hose. This cover material can be molded onto spring 36 or wound on with interlocking strips, as is common practice in present day hose manufacturing. Vinyls and other polymers may be used for cover materials 32 and 34 to make them thin, but also strong and durable and easy to bond to one another. Cover materials 32 and 34 is bowed outward between the spring coils as it is molded around the spring coil. This gives the cover material for the prior art design room to move out of the way when the hose retracts and spring coils 36 are forced close together (see FIG. 1B). Preferably, the spring would continue this retracting force, even when the hose is in its fully compressed (retracted) state. Bias spring 36, thus, can be a coiled spring that is biased to provide a retracting force even when fully retracted. From this naturally retracted state, the spring is stretched as the hose cover materials 32 and 34 are placed over it. Then, when the hose is released, hose 30 would take on its naturally retracted state. The spring can continue to exert a significant retracting force even with the hose is in its fully extended position (see FIG. 3B).
FIG. 1A shows prior art hose 30 in its substantially extended state. Cover material 34 (layer 34) provides most of the pressure support and may have a mesh of fibers within a more flexible material to help withstand higher pressures. Cover material 32 can be molded on top of spring coils 36 (compression biased spring) and cover material 34 to hold the entire system together. Because this is a pressure hose, materials 32 and 34 protrude (or bow) outward in between the coils of spring 36. This slight outward bow assists the hose in keeping the cover material from getting trapped between the adjacent coils of bias spring 36. Notice that the outward extending of cover materials 32 and 34 significantly increase the volume of the hose in both its retracted and extended positions compared to the cylindrical volume of spring 36 in its retracted and extended positions of the same length, respectfully. The disclosed invention removes this additional volume problem by indenting and folding the hose body material inside the helical biasing spring.
FIG. 1B shows prior art hose 30 only partially retracted with further contraction possible as cover material 34 is compressed and makes contact with itself on the inside the hose. Ideally, the biasing spring would continue to contract the hose until cover material 34 is stopped by contact with itself. This means that the cover material need to be flexible to allow easy stretching and contracting. Cover material 34 mounted on the inside of the spring coil providing most of the pressure holding ability of the hose. Spring 36 acts as a support structure for hose cover material 34 to keep it from expanding radially too far. Cover material 32 basically provides a water proof cover for the spring and also helps hold cover 34 in place on the spring coils. Cover materials 32 and 34 must be relatively strong in the plane of the material to resist the pressure forces created by a pressurized fluid flowing within it. This strength also means that the hose body will not be easily stretched longitudinally or around its circumference (hoop strain). In other words, cover materials 32 and 34 can be folded, but are not easily stretched. Thus, cover materials 32 and 34 in prior art hose 30 need to be bowed out to allow space for the materials to fold out of the way of adjacent cover material and from between spring coils 36. Notice that the cover material may fold under itself to allow the spring to contract more fully (see FIG. 1B). If the bowing out of cover materials 32 and 34 is made too small, the hose body (cover materials 32 and 34) can get bunched up between the coils of the spring 36 and greatly reduce the amount of retraction possible for the hose. In the disclosed hose design, the hose body is folded inward from the spring coils (the opposite of prior art). This allows the cover materials to crumple into the space within the biasing spring. This reduces the volume of the hose when retracted and also protects the hose body from damage.